The fact of the matter is you can't use priority mail supplies to send items first class. Besides, cutting down labels, many turn prioity mail boxes inside out and sent first class.

I use cut down prioity mail labels all the time. I also occasionally use prioity boxes as first class. What I don't do is let the PO see me do it.

It seems to me that the clerk did what he/she had to do. If he/she didn't report to a supervisor and was being watch by a supervisor, that cleck would have gotten into trouble.

BTW, when I use cut down labels, I leave no red or blue, only white.